1. Field of the Invention
The present invention relates to an improvement related to the apparatus for detecting seated condition for toilet seat which detects whether a human body is seated on a toilet seat or not.
2. Description of the Related Art
In recent years, a toilet seat apparatus for washing the rectal area of a human body has been spreading. This apparatus washes or dries by warm air the rectal area of a human body, therefore thanks to this apparatus, a person can use the toilet healthfully and comfortably.
In the conventional toilet seat apparatus for washing the rectal area of a human body, there has been a apparatus for detecting a seated condition for toilet seat which detects whether a person is seated on a toilet seat or not. This conventional apparatus for detecting seated condition for toilet seat detects the approach of a human body to a toilet seat or detects a change in electrostatic capacity between electrodes by the contact. For instance, this conventional apparatus is described in Japanese Unexamined Patent Publication No. 258423/1992 (Kokai).
The apparatus described in Japanese unexamined Patent Publication No. 258423/1992 (Kokai) includes a determining circuit. This conventional determining circuit converts electrode capacity between one conductor and the other conductor to voltage, the other is provided in the inside of the toilet seat as the other electrode in the same way as one conductor as one electrode, by using electrostatic capacity-voltage conversion circuit. (As the other electrode, the ground may be used instead of the other conductor.) The determining circuit also determines whether a human body sits on a toilet seat or not by comparing the voltage obtained in the above-mentioned way with the amount of criterion which is predetermined in advance and this criterion amount is the fixed amount having the predetermined range which is set when the power source is inputted.
However the above-mentioned conventional apparatus has the following disadvantage because the amount of criterion is the fixed amount. The electrostatic capacity between two conductors is affected by the size, temperature and humidity of a human body. Therefore even if the seated or un-seated condition is in the same state, the amount of electrostatic capacity varies in response to each person's condition. When the variation of electrostatic capacity caused by the variations in size, temperature and humidity of a human body is too large to correspond, an error of detection occurs in.